Cloud-based revenue management company Model N has made a lot of money for insiders and investors with its $100 million IPO but it hasn't been an overnight success story.

The Redwood City company led by CEO Zack Rinat has been around for 13 years and took its last venture funding round back in 2003.

"We joke that this is our bar mitzvah, our coming of age, not our birthday," Israeli native Rinat told me after ringing the opening bell on the New York Stock Exchange on Wednesday. "We actually had more cash on hand when we went public than we got in that last funding round."

Model N's shares (NYSE:MODN) sold for $1 more than the top end of their expected range in the funding stage of the IPO, going for $15.50 each. Then they leapt on investor enthusiasm in their market debut, soaring as high as $22.25 — up by nearly 44 percent. The stock closed at $19.98.

Model N is the second successful tech IPO this year, following last week's debut by Redwood City-based Silver Spring Networks (NYSE:SSNI). The smart grid tech company led by CEO Scott Lang also raised more than expected in its $81 million offering and soared by more than 30 percent on its first day of trading.

San Francisco-based Marin Software, led by CEO Chris Lien, hopes to keep the streak of successful Bay Area tech IPOs alive when it goes public later this week. It is expected to raise as much as $91 million when it prices on Thursday before hitting the NYSE on Friday.

"Investors are looking for good enterprise software companies like ours to invest in," a very happy Rinat told me.

Rinat sold his previous company, NetDynamics, to Sun Microsystems a year before starting Model N. The original idea was to unify pieces of software used to track and manage revenue streams in one place.

"We have been cash flow positive for a number of years," Rinat said. In its IPO filing, Model N showed net income of $624,000 in 2010 and $1.48 million in 2011. Then it turned on the spending in 2012 in preparation for this year's IPO, showing a $5.69 million loss last year.

Revenue jumped by more than two-thirds in the last three years to hit $84.26 million in 2012.

Model N originally targeted the life science industry and counts Amgen and Johnson & Johnson among its biggest current clients. But beginning in 2006 it started winning tech customers including Dell and VMware.

Along with executives, board members and representatives of those biggest customers, Rinate brought 50 Model N workers that have been with the company from the beginning to the NYSE for the opening bell festivities.

"There are a lot of people who have been with us for a very long time and that is unusual in Silicon Valley," Rinat said on Wednesday. About 170 of the company's 600 workers have been at Model N more than five years.

"This IPO wasn't about the money," Rinat told me. "We were looking testimony in the public markets that we are going to be around for a long time."